CD38 is a multifunctional protein having function in receptor-mediated adhesion and signaling as well as mediating calcium mobilization via its ecto-enzymatic activity, catalyzing formation of cyclic ADP-ribose (cADPR) and ADPR. CD38 mediates cytokine secretion and activation and proliferation of lymphocytes (Funaro et al., J Immunol 145:2390-6, 1990; Terhorst et al., Cell 771-80, 1981; Guse et al., Nature 398:70-3, 1999). CD38, via its NAD glycohydrolase activity, also regulates extracellular NAD+ levels, which have been implicated in modulating the regulatory T-cell compartment (Adriouch et al., 14:1284-92, 2012; Chiarugi et al., Nature Reviews 12:741-52, 2012). In addition to signaling via Ca2+, CD38 signaling occurs via cross-talk with antigen-receptor complexes on T- and B-cells or other types of receptor complexes, e.g., MHC molecules, involving CD38 in several cellular responses, but also in switching and secretion of IgG1. CD38 is expressed on various malignant cells.
Anti-CD38 antibodies are being developed for the treatment of multiple myeloma and other heme malignancies. The antibodies are either injected or infused via the intravenous (IV) route. The amount of antibody that can be administered via the intravenous route is limited by the physico-chemical properties of the antibody, in particularly by its solubility and stability in a suitable liquid formulation and by the volume of the infusion fluid.
Therefore, there is a need for additional anti-CD38 antibody formulations and pharmaceutical compositions.